Centralized traffic control system for railroads



Nov. 13, 1962 c. JAcHlNo 3,064,126

CENTRALTZED TRAFFIC CONTROL SYSTEM FOR RAILROADS Filed May 2o, 195'/ esheets-'sheet 1 .5. D om @E wf i". will, .I

Nov. 13, 1962 c. JACHlNo CENTRALIZED TRAFFIC CONTROL SYSTEM FORRAILROADS Filed May 20, 1957 6 Sheets-Sheet 2 INVENTOR. C. JACHNO HISlATTORNEY Nov. 13, 1962 c. JAcHlNo 3,064,126

CENTRALIZED TRAFFIC CONTROL SYSTEM FOR RAILROADS Filed May 20, 1957 6Sheets-Sheet 3 HIS ATTORNEY m v n m MMHMGLHE MANU .Q .o WW n mC n A J Cw .7 m @M I- UL N 0.5.45 Y N .Qz .w w k Il .0.545 Q N w C. JACHINO Nov.13, 1962 CENTRALIZED TRAFFIC CONTROL SYSTEM FOR RAILROADS Filed May 20,1957 6 Sheets-Sheet 4 V6@ Ei EQ mo wm. t S 51.9 Vai@ R. m O N vit MANU-..OEE wl w .Qzfw mH A van: E E C @H045 1A AJH H @z m #Hp c m7,/

C. JACHINO Nov. 13, 1962 CENTRALIZED TRAFFIC CONTROL. SYSTEM FORRAILROADS Filed May 20, 1957 6 Sheets-Sheet 5 INVENTOR. C. JACHINOHIS'ATTORNEY @mwa C. JACHINO Nov. 13, 1962 CENTRALIZED TRAFFIC CONTROLSYSTEM FOR RAILROADS Filed May 20, 1957 6 Sheets-Sheet 6 United StatesPatent C M 3,064,126 CENTRALHZED TRAFFEC CGNTROL SYSTEM FDR RAILRADSCarlo Jachino, Bologna, Italy, assigner to General Rallway SignalCompany, Rochester, NX. Filed May 20, B57, Ser. No. 660,153 9 Claims.(Cl. 246-5) This invention relates to centralized trac control syS- temsfor railroads, and more particularly pertains to centralized controlsystems wherein track switches and signals at spaced intermediatestations may 'be controlled manually from a remote control oice, or theymay be controlled automatically through the control oihce upon theapproach of a train.

In general, the route of a train through a particular eX- tended sectionof trackway may be determined upon entrance of the train into thecentralized traffic control (generally known as CTC) territory,particularly on double track railroads. Thus, if the point of entranceto the CTC territory and the point of departure from the territory aredesignated, it should be unnecessary for an operator to designate thepositioning of track switches and the clearing of signals atintermediate points, except as may be required in accordance with localconditions that may occur at the intermediate interlockings duringprogress of a train through the territory. :It is therefore necessarythat an operator 'be able to cont-rol manually the track switches andsignals a-t intermediate interlockings in a centralized traffic controlsystem, but it is also desirable to -be able to permit the establishmentof routes automatically where there are no unusual conditions callingfor manual route designation.

Generally speaking, and without attempting to deline the scope of thepresent invention, the system according to the present inventionprovides in a CTC system, for the setting up of partial routesautomatically and progressively in advance of a train as the trainprogresses through the CTC territory. Thus no operation is required onthe part of an operator to establish a route for a train throughintermediate interlockings within the CTC territory.

It is provided, however, that the operator can take over semi-manualcontrol of intermediate interlockings involved in the route of a trainso as to hold a train as required to give priority to certain conictingroutes. This can be done on the basis of semi-automatic operation inthat, with a selector lever positioned for semiautomatic control,partial rou-tes are selected automatically as in full automaticoperation, but manual designation must tbe made to execute the partialroute controls for 'the different stations, rather than having this doneautomatically upon the passage of a train through certain tracksections. By this organization there is no possibility of the CTCoperator aligning the wrong route for a train aS the route is determinedautomatically in accordance with a prior designation of a point ofdeparture from the CTC territory, and no different route may beestablished.

Full manual control irrespective of a predetermined point of departurefor a train may be had by operating the selector lever to a full manualposition. With the selector lever in this position, the system isoperable according to conventional CTC operating principles.

An object of the present invention is provided for the automaticoperation of track switches and signals that are subject to CTC controlat several intermediate stations in accordance with the designation ofarrival and departure points in lthe territory governed lby CTC.

Another object of the present invention is to provide for the automaticestablishment of partial routes in advance of a train as the trainprogresses.

Another object of the present invention is to provide for semi-automaticoperation in a CTC system wherein 3,064,126 Patented Nov. 13, 1962 HCCthe route that may be established is automatically determined, but itsactual establishment requires manual designation.

Another object of the present invention is to select, when desired, fullmanual control of track switches and signals like in a conventional CTCsystem as compared to automatic or semi-automatic operation.

Other objects, purposes, and characteristic features of the presentinvention will be in part obvious from the accompanying drawings and inpart pointed out as the description of the invention progresses. l

ln describing the invention in detail, reference is made to theaccompanying drawings in which corresponding parts in the severalfigures of the drawings are identified by similar reference characters,in which parts having similar functions are designated by similar letterreferenc-e characters, and in which:

FlG. 1 is an illustration particularly by -block diagram of the CTCsystem provided by the present invention aS applied to a specific tracklayout;

FIGS. 2A, 2B, 2C, and 2D when arranged one above the other respectivelyillustrate a circuit organization for apparatus that is mostly at acontrol oflice for the selection of track switch and signal controlslfor communication to respective lield stations;

FIG. 3 illustrates a typical circuit for the automatic or manualinitiation of CTC code communication apparatus into a cycle ofoperation;

FIG. 4 is a sequence chart illustrating the sequence of operation ofcertain relays upon passage of a train over a particular route when theCTC system is made subject to automatic cont-rol.

For the purpose of simplifying the illustrations and facilitating in theexplanation thereof, the various parts and circuits constituting thisembodiment of the present invention have been shown diagrammatically,and certain conventional illustrations have been employed, the drawingshaving been made more for the purpose of facilitating the `disclosure ofthe present invention as to its principles and mode of operation ratherthan for the purpose of illustrating the specific construction andarrangement of parts that would be employed in practice. Thus, thecircuits are shown schematically and symbols are used to indicateconnections to the terminals of batteries or other sources of electriccurrent. The symbols and are employed to indicate connection to thepositive and negative terminals respectively of suitable batteries orother sources of direct current, and the symbols (B+) and (B-) are usedto indicate connections to the opposite terminals of a suitable batteryor other direct current source which has a center or intermediateconnection designated as (C).

It is to be understood that the system provided by the present inventionis applicable to the control of power track switches and signals invarious different types of track layouts, and that the control of thetrack switches and signals illustrated in this embodiment of the presentinvention is to be considered as typical of the manner in which controlcan be provided for ditferent combinations of track switches and signalsthat may be provided indifferent track layouts to 'be encountered inpractice.

For the purpose of disclosure of this embodiment of the presentinvention, however7 it is assumed that the system is applied to thecontrol of switches and signals disposed along a typical portion orterritory of a railroad as illustrated in FIG. l that is governed by aCTC control system. The track layout illustrated in FIG. 1 provides fordouble track operation, the upper track being provided for traflic fromright to left, or westbound traflic, and the lower track in the trackdiagram being provided for governing traflc to the right, or eastboundtralc.

An entering signal 10 is provided Ifor governing westbound traliic intothe westbound track 30, this signal being at field station A and beingsubject to CTC control from the control oiiice. -Spaced some distancefrom the signal 10 are lower and upper arm signals 11 and 12 governingtraic over a track switch 2W into tracks 31 and 32 respectively. Thesetrack switches and signals are at iield station B and are subject tocontrol by CTC from the control oliice. Included in the stretch of track31 is a group of track switches and signals for governing westboundtraic at eld station C. This group includes the track switches 3W and 4Wand signals 13, 14, 15, and 16. A signal 17 is provided for governingwestbound traiiic upon leaving the CTC control territory illustrated inFIG. 1. This signal 17 is controlled through iield station D in thecentralized tratlic control system.

Although only CTC control signals are illustrated, it is to beunderstood that suitable, automatic block sig- Daling is provided alongthe trackway between the various eld stations Vas required. It is to beunderstood that a similar track layout is provided for the passage ofeast bound traffic, and inasmuch as the mode of operationrover theeastbound track would be comparable to that for the westbound track, forthe purpose of simplification of the disclosure of the presentinvention, the disclosure has been made more particularly relative tothe control of signals for westbound traic, and it is to be understoodthat similar apparatus, and a similar mode of operation is elective inthe setting up of routes yfor eastbound traiiic.

The code communication apparatus provided for transmitting track switchand signal controls from the control oilice to the several fieldstations and for transmitting indications to the control oce as to theconditions of apparatus at the eld stations can be of any suitable type,such, for example, as by the code communication systern disclosed in theU.S. patent of W.D. Hailes et al. No. 2,399,734, dated May 7, 1946. Itis therefore believed unnecessary to describe in detail the operation ofthe code communication apparatus as reference can be made to the Haileset al. PatentV No. 2,399,734 for a complete disclosure of the structureand mode of operation of the system. Y v

The CTC control machine for designating controls to be communicated tothe respective field stations according to the 'present invention is,however, dilerent from that disclosed in the above mentioned Hailes etal. Patent No.' 2,399,734, and typical sections of the control panel areillustrated in FIG. l wherein panel section 33 is provided yfor thedesignation of controls for field station B and the panel section 34 isprovided for the designation f controls for tield station C. It is to beunderstood that additional panel sections are provided as required forthe control of track switches and signals at other eld stations.

The panel section 33, `for example, has a 3-position automatic-manualselector switch 11-12AM for use in the designation of controls forstation B for governing westbound traic. These three positions areprovided respectively for automatic control, semi-automatic control, andmanual control in the setting up of routes. Route buttons 11lB and 12PBare provided for the designation of Vroutes governed by the signals 11and 12 respectively at field station B. A 2-position lever 1l-12SGL isprovided on panel section 33 as a means for manually designating acontrol for putting a signal to stop. With reference to FIGS. 2A, 2B,2C, and 2D, magnetic stick indication relays GK, PK, AK, RK, and CS areillustrated as being subject to control by the code communicationapparatus, and thus these relays are all provided at the control oflceand are controlled by the code communication apparatus to indicateconditions of apparatus inthe field.

Route description storage relays RS, BR, and CR are provided at thecontrol office for storing route descriptions used in controlling trackswitches and signals at the different field stations.

A relay F is associated with each of the banks of storage relays RS, BR,and CR for the purpose of permitting only one route description storageto be entered into the associated storage bank at one time.

A partial route control relay Pr is provided at the control otlice foreach of the intermediate field stations for the registration in theautomatic control apparatus of a condition where a partial route isestablished.

Relays G are provided for the respective signals, and these relays checkas to when conditions are right for the clearing of a signal.

Route relays RR are provided for causing the transmission of routecontrols to the respective vfield stations for setting up the partialroutes as they are called for through the several field stations inaccordance with the progress of a train.

Having thus considered the general organization of the apparatusemployed in this embodiment of the present invention, furtherdescription of the system will be set forth upon consideration of themode of operation of the system under typical operating conditions.

OPERATION Normal Conditions In describing the mode of operation of thesystem consideration will iirst be given as to the normal conditions ofthe system with no trains present and with no routes established. Underthese conditions, most of the relays illustrated in FIGS. 2A,-2B, 2C,and 2D are in their dropped away positions. The relays F, however, arenormally energized to indicate that no route is established through theassociated station. Relay 10P (see FIG. 2A) is normally energized by acircuit extending -from (-1-), including back contacts 3S, 36, 37, 38,and 39 of relays RSI, RS2, R83, 10G and 16GK respectively and winding ofrelay 10F, to This relay must be energized in order that a routedescription may be set up which can eventually cause the clearing ofsignal 10. Similarly associated with field station B, the relay 11-12Fis normally energized by a circuit extending from including backcontacts di), 41, 42, 43, 44, 45, 46, and 47 of relaysrBRl, BRZ, BRS,HRR, 12RR, llGK, 12GK, and A-BPr, and winding of relay 11-12F, to Therelay 13-14F which is associated with iield station C is normallyenergized by a circuit extending from (-l-) including back contacts 4S,49, 50, 51, 52, 53, and 54 of relay CRL CRZ, 13RR, MRR, 13GK, 14GK, andB-CPr, and winding of relay 13-14F, to

Y Other relays that are normally energized include the track relays TRwhich are energized according to usual practice and are subject to beingdropped away upon the shunting of lthe track rails of an associatedtrack section T by a train. Track relays UTR and 1TR illustrated in FIG.l are associated with the track sections 0T and 1T and are normallyenergized. These relays are typical of track relays provided at variouspoints along the trackway according to usual practice.

Automatic Operation To consider the mode of operation of the systemunder automatic operation, a typical mode of operation will be describedfor the passage of a westbound train through the CTC territoryillustrated in FIG. 1. The route to be specifically considered will bethe route for a train entering at signal 10 and leaving the CTCterritory at signal v17. It will be considered that designation of theapproach of a westbound train to the CTC territory is made by a -stationmaster, or by other suitable means, which can be eiected by theactuation of the push button PBZ of FIG. 2A for purpose of illustration.This push button PBZ may be located at a station platform,

for example, ywhere it may be actuated when a train is prepared to leavethat station. The actuation of this push button PEZ is effective overthe code communication apparatus to actuate a magnetic stick relay CS2at the control oice to its picked-'up position. Relay CS2 isparticularly indicative of the above described route through the CTCterritory, and similar relays CST; and C83 are also provided at thecontrol oflice to be responsive to the actuation of similar push buttonsPB (not shown) by a station master for the designation of routes throughthe track layout other than the above mentioned route that will beconsidered in detail.

The picking up of relay CSZ closes a circuit at front contact S5 for theenergization of an indicator lamp CSK to call to the attention of theoperator of the machine at the control oiice that a route has beendesignated through the CTC territory for the train entering at signal toleave the territory at signal 17. Thus, if the operator of the controlmachine is willing to let the route be automatically' establishedthrough the CTC territory he actuates the push button ltPBZ on hiscontrol panel. The actuation of this push button ltPBZ causes thepicking up of relay RSZ by the energization of a circuit extending frorn(-j-), including back contact 56 of relay NPK, front contact 57 of relay10F, back contact 5S of relay CS1, front contact 59 of relay CS2,contact 66 of button lPBZ in its depressed position and winding of relayRSZ, to Relay RSZ is maintained energized by a stick circuit extendingfrom (-i-), including back contact 56 of relay lPK, front contact 6l ofrelay RSZ, Contact 60' of button JlPBZ in its normal position andwinding of relay RSZ, to Contact 6d of button lPBZ is preferably a makebefore break contact so that the stick circuit for relay RSZ isestablished upon the picking up of that relay and is maintained when thebutton is restored to its normal position so that there is no momentarydeenergization of Irelay RSZ upon the restoration of the push buttonNPBZ to its normal position. The picking up of relay RSZ causes therestoration of relay CSZ to its dropped away position by theenergization of a drive-down winding through front contact 95 of relayRSZ and front contact 96 of rrelay CSZ.

The picking up of relay RSZ opens the stick circuit that has beendescribed for the relay idF at back contact 36, and thus causes therelay IGF to be dropped away. Upon the dropping away of relay lliiF, therelay ltG, which is associated with the selection of a control forclearing signal d, becomes picked up by the energization of a circuitextending from (-5-), including back contact 35 of relay RST, frontcontact 36 of relay RSZ, back contact 62. of relay MF, back contact 63of relay 11-12PK, front contact d4 of relay ll-'EZR back contact 65 ofrelay A-BPr and winding of relay MiG, to Upon the picking up of relayNBG, a stick circuit is closed for that relay at front contact 1.32shunting front Contact 6d of relay ll-llZF and back contact 65 of IrelayA-BPr out of the pick-up circuit just described. The picking up of relay10G is effective to automatically initiate the code communicationapparatus into a cycle of operation for transmission of controls toiield station A, and because of the closure of its front contact 66, acode is selected for transmission to field station A for the clearing ofsignal 10. The reception of this control at station A causes the signal10 to be cleared subject to the usual track circuit safety circuits thatare employed in the iield. This signal control when received in the eldcauses the picking up of the magnetic stick relay NGI which is used toprovide an indication when a train accepts signal l as will behereinafter considered.

A typical system that may be employed for automatically initiating thecode communication apparatus into a cycle of operation in carrying outthe mode of operation described above is found in FIG. 3, wherein anormally energized start relay NFB? is provided for the initiation ofthe system. This relay is subject either to manual or 6 automatic startcontrol. Relay 10PB'P is normally energized by a circuit extending from(-1-), including normally closed contact 118 of push button I'PB, backContact 119' of relay 10G, Winding of relay 10PBP, back contact l2@ ofrelay 10G, resistor R1 and normally closed contact 4;21 of push buttonIPB, to

It will be noted that contacts 1119 and 1Z0 of relay NG are connected inpole changing relationship, so that the shifting of relay lG either toits picked up or its dropped away position causes the pole changing ofthe relay lPBP so as to drive the relay down. Because of the inclusionof the resistor R1 in the circuit for relay liiPBP, the relay PBP doesnot receive suicient energy on Ireversed polarity to become picked upuntil the resistor R1 is shunted by front contact 122 of relay 10CHconnected in series with back contact 123 of relay LCS. in other words,it is insured that the relay MCH has time to become picked up before therelay IOPBP is restored to its normally energized condition, after anautomatic starthas been initiated. When the relay MPE? is dropped away,the closure of its back contact 124 causes the picking up of relay MCHby the energization of an obvious circuit. Relay 10CH when picked up ismaintained energized by a stick circuit extending through back contactlZS of relay MLC and front contact 126 of relay MCH.

Relay MECH is effective when picked up to pick up relay lilLC by theclosure of its front contact 127. This circuit is indicated by a dottedline 128 to show that other circuit connections are provided accordingto the above mentioned Hailes et al. patent for the purpose ofpermitting only a single start to be effective at one time. Thus, inactual practice, the circuits for the relays LC for the several stationsare provided as a chain circuit `network to permit only a single relayLC to be icked up at one time. In response to the picking up of a relayLC, such as the picking up of relay 10LC, a system relay LCS is pickedup as by the closure of front contact 129 of relay NLC, and the pickingup of this relay, as disclosed in the above mentioned Hailes et al.Patent No. 2,399,734 sets the system into operation for the transmissionof the selected controls to the particular field station for which thestart has been rendered elective as is indicated in FIG. 3 by theclosure of front contact 13d. It will be readily apparent that this samecircuit organization is effective upon the dropping away of the relayMEG upon cancellation of the route established to initiate the codecommunication apparatus by pole changing the relay ltlPBP so as to-transmit a signal stop control to restore the signal control apparatusto its normal condition. The initiation of the system manually fortransmission of controls to field station A can be effected by theactuation of the start push button lPB which will cause the droppingaway of the start relay ltPBP by opening its circuit at normally closedpush button contacts lll and 121. The restoration 'of the push buttonltiPB to its normal position conditions the circuit for relay IGPBF sothat it can be restored to its normally energized condition.

The relay NLC is effective during a cycle to select the transmission ofa station call code for iield station A and to render the transmissionof asignal control code selected by relay lG effective.

When signal 10 has been cleared, an indication that the signal has beencleared is transmitted to thecontrol cnice by the code communicationapparatus,land thus the signal clear magnetic stick indication relayIGGK becomes picked up at the control oice.

The picking up of relay IGK provides for the transfer of the routedescription storage into the storage yrelays BR, and inasmuch as therelay RSZ has been assumed to have been energized for the typical routebeing considered, the relay BRZ becomes energized when the signal clearindication is received. Thus the relay BRZ becomes picked up by theenergization of a circuit extending vfrom (-4-), including back contact67 of relay 11-12PK, back contact 68 of relay 11-12CP, front contact 69of relay 11-12F, front contact 70 of relay 10GK, front contact 71 ofrelay RSZ, and winding of relay BRZ, to This relay when picked up ismaintained energized by a stick circuit extending from (-l-), includingback contact 67 of relay 11-12PK, back contact 68 of relay 11- 12CP,front contact 72 of relay BRL. and winding of relay BRZ, to

The picking up of relay BR2 opens the circuit that has been describedfor relay 11-12F at back Contact 41 and causes this relay to be droppedaway. Upon the dropping away of relay 11-12F a circuit is closed for theenergization of relay 11G extending from (-l-), including back contact40 of relay BRI, front contact 41 of relay BRZ, back contact 73 of relay11-12F, back contact 74 of relay 11-12AK, front contact 75 of relay13S-141:, back contact 76 of relay 13-14PK, back contact 77 of relayB-CPr and Winding of relay 11G, to It Wiil be noted that relay 11G isselected in preference to the relay 12G V because of the relay BRZ beingin its energized condition rather than the relay BRS. In other Words,the route through the CTC territory from end to end is stored by therelay BR that is energized, and the relay BRZ has selected theenergization of relay 11G rather than relay 12G because it is theclearing of signal 11 that is required for fulfillment of the throughroute that has been designated for the train.

Upon the picking up of relay 11G, the route relay 'MRR becomes picked upby the energization of a circuit extending from including back contact78 of relay IZRR, front contact 79 of relay 11G, contact 80 of leverII-IZAM in its left-hand position, and winding of relay -MRR, to Thisrelay when picked up causes the transmission of a signal clearing codefor the clearing of signal 1:1 by the closure of its front contact 81,and the closure of its front contact 82 provides for the transmission ofa switch control to field station B for operating the track switch 2W toits reverse position. Upon the clearing of signal 111,` an indication isreceived over the code communication apparatus to cause the picking upof the signal clear magnetic stick relay IIIGK at the control oirice.

, No further propagation of partial route establishment is effectiveuntil a Westbound train actually accepts the signal because it isdesirable to leave field station C free for the establishment ofconicting routes such as a route governed by signal or signal 16. It isconsidered,

however, that after a train has passed signal 10, the

route for the train should then be extended through field station C, andthe automatic establishment of the partial route through this eldstation is thus initiated.

With reference to FIG. l, the relay 10P becomes energized after a trainhas accepted signal 10, and after the track section 0T has becomeunoccupied in the rear of the train. An indication of the energizedcondition of this relay is then transmitted to the control oiiice toinitiate the establishment of the partial route through field station C.It has been pointed out that the magnetic stick 'relay 10GP has beenpicked up in accordance with the transmission of a ocntrol for theclearing of signal 10, and thus upon entrance of the westbound traininto the track section 0T in approach of signal 10, the dropping away ofrelay 0TR establishes a pick-up circuit for the relay Pa extending fromincluding iront contact 83 of relay 10GP, back contact 84 of relay GTR,front contact 85 of relay 1TR and Winding of relay Pa, to This relaywhen picked up closes its stick contact 86 to shunt front contact 85 ofrelay ITR out of the circuit just described.

With the relay Pa in its picked-up condition, a circuit is conditionedfor the energization of relay 10P so that this relay can be picked up assoon as the train has accepted signal 10 and the track section 0T hasbecome unoccupied in the rear of the train. The picking up of relay GTRcauses the picking up of relay 10P by the closure of a circuit for theenergization of relay 10P extended from (-i), including front contact 83of relay MGP, front Contact S4 of relay 0TR, back contact 87 of relay1TR, iront contact 88 of relay Pa, and Winding of relay :10P to Thepicking up of this relay closes a stick circuit at front contact 89shunting the track contacts out of the circuit just described. Theclosure of front contact 90 of relay 10P causes the transmission to thecontrol oiice of an indication that the relay 10P has become picked upand this indication is effective to initiate establishment of a routethrough ield station C for the Westbound train.

It will be noted that the control of relay 10P is such as to insure thepresence of a train as compared to conditions causing momentary droppingof a track relay as by the accidental shunting of the track rails by amaintenance workman. Thus the track section 0T must be shunted first,and then the track section 1T must be maintained shunted after the trainhas left the track section 0T It is to be understood, however, thatother types of train presence detecting means, such as treadles and thelike, may be employed in accordance with the requirements of practice.

With reference to FIG. 2A, the magnetic stick relay 10PK at the controlofrice is actuated to its picked-up position in response to the pickingup of relay 10P at eld station A, and the picking up of this relaycauses the picking up of the partial route relay A-BPI. The circuit bywhich relay A-BPr is picked up extends from including normally closedcontact 91 of the cancel button B-CPB, back contact 92 of relay 11-12PK,front con` tact 93 of relay 10PK and winding of relay A BPr, to Thepicking up of this relay closes a stick circuit at front contact 94 toshunt front contact 93 of relay 10PK out of the circuit just described.

The picking up of relay 10PK causes the dropping away of relay 10G bythe opening of its circuit at back contact 63, and the dropping away ofthis relay transmits a signal stop control in accordance with theclosure of its back contact 66 to iield station A to cause the droppingaway of relay 10GP.

Upon the picking up of relay A-BPr, relay CRZ becomes picked up inaccordance with the extension of the route through iield station C. Thecircuit by which relay CRZ is energized extends from (-1-), includingback contact 97 of relay 1.3-14PK, back contact 9S of relay 12a-MCP,front contact 99 of relay 13-14F, front contact 100 of relay A-BPI',front contact 10."` of relay 11GK, front contact 102 of relay BRZ andwinding of relay CRZ, to A stick circuit is established for this relayextending from (-5-), including back contact 97 of relay 134413K, backcontact 93 of relay 13-14CP, front contact 103 of relay CRZ and windingof relay CR2, to

The picking up of relay CRZ causes the dropping away of the relay 13-14Fby the opening of its circuit at back contact 49. inasmuch as theenergization of relay CRZ is indicative of a through route with an exitpoint at signal 17, the energization of this relay causes the energize.-tion of relay 13G which. is associated with the clearing of signal 13which in turn governs the partial route to be established through iieldstation C over track switch 4W in the reverse position. Thus, the relay13G becomes picked up upon the energization of relay CRZ by theenergization of a circuit extending from (-1-), including back contact48 of relay CRI, front contact 49 of relay CRZ, back contact 104 ofrelay 13-14F, back contact 105 of relay 13-14AK, front contact 106 ofrelay 17F, back contact 107 of relay 1713K, lback contact 108 of relayC-DPr and Winding of relay 13G, to

Relay 13G when picked up causes the picking up of the partial routerelay 13RR by the closure of a circuit for this relay extending from(-l-), including back contact 109 of relay 16RR, back contact 110 ofrelay ISRR, back contact 111 of relay MRR,V front contact 112 ofmagnetic stick relay GP at that station.

9 relay 13G, contact 113 of lever 1.3-14AM in its left-hand position andwinding of relay 13RR, to The picking up of this relay closes a circuitfor relay 13G at front contact 131, shunting contacts 10S, 106 and 167of relays 13-14AK, 17F and 17PK out of the picked up circuit for therelay 13G.

The picking up of relay 13RR is effective by the closure of its frontcontact 115 to cause the transmission of a signal clearing code to fieldstation C for the clearing of signal 13. A switch control is alsotransmitted in accordance with the closure of front contact 1in of relay1ERE to operate the track switch 3W to its normal position. The closureof front contact 117 of relay 13RR causes the transmission to fieldstation C of a control for operating track switch 4W to its reverseposition. Thus, the route becomes established through track switch 3W inits normal position and over track switch 4W in its reverse position,and the signal 13 becomes clear to establish a route for the westboundtrain to leave the CTC territory at signal 17. Upon the clearing ofsignal 13, an indication is transmitted to the control ofiice that the-signal has been cleared, and accordingly the magnetic stick relay 13GKat the control office becomes picked up.

Having thus considered the mode of operating upon establishment of thethrough route, consideration will now be given as to the mode ofoperation in the restoration of the apparatus to normal conditions afterthe passage of a westbound train over the route extending from signal 10to signal 17.

lt has been pointed out. that the relay 10PK (see FIG. 2A) is picked upafter passage of 'thetrain past the signal 1l). This relay when pickedup causes the dropping away of the through route description storagerelay RSZ by the opening of its circuit at back contact 56. Signal 10 isrestored to stop automatically in the field according to usual practice,and an indication that the signal has been restored to stop istransmitted to the control ofiice, and lis effective to actuate themagnetic stick relay NGK to its dropped away position.

As the train progresses further in the route so as to have passed thesignal 11G which is associated with station B, relay 11-12PK is pickedup at the control ofiice by control means (not shown) similar to thecontrol means that has been described in detail for the energization ofthe relay NPK which is controlled from station A. The picking up ofrelay 11-12PK at the control ofiice causes the dropping away of relay MGby the opening of its circuit at back contact 63, and the dropping awayof relay ltG closes a circuit at its back contact 33 that has beendescribed whenV considering the normal conditions ofthe system forrestoring the relay 10F to its normally energized position. The relay10G in dropping away is etfective to initiate the code communicationsystem into a cycle of operation to transmit a control which isindicated by a dotted circuit associated with contact 66 to fieldstation A to cause the dropping away of the With reference to FIG. 1,the dropping away of relay lfiGP causes the dropping away of relay itil)at field station A by the opening of front contact 83. Relay 10P whendropped away closes its back contact 90 which is effective to cause thetransmission of an indication to the control office that relay 10i hasbeen dropped away, which upon reception at the control ofhce causes therelay 10PK to be actuated to its dropped away position. This completesthe restoration to normal conditions of the apparatus associated withfield station A.

A similar mode of operation is effective for restoring the apparatus tonormal at field station B wherein the picking up of relay 11-12PK opensthe circuit for the through route description storage relay BRZ at backcontact 57 so as'to cause that relay to be dropped away. The droppingaway of relay BRZ causes the dropping away of relay 11G by the openingof its circuit at front contact 41. The circuit by which the relay 11Ghas been maintained picked up prior to this time extends from includingback contact 40 of relay BRl, front Contact 41 of relay BR2, backcontact 73 of relay 11-12F, front contact 133 of relay 11RR, backcontact 77 of relay B-CPr and winding of relay 11G, to Upon the droppingaway of relay 11G, the route relay 11RR becomes dropped away by theopening of its circuit at front contact 79 of relay 11G. When relay 11RRbecomes dropped away, it initiates the transmission of a control tofield station B automatically for restoration of the signal controlapparatus at that field station to its normal conditions according to amode of operation similar to that which has been specifically describedfor the restoration of normal conditions of the apparatus associatedwith field station A. Such mode of operation causes the transmission ofan indication from field station B to the control office to restore therelay 11-12PK to its dropped away position. When the signals at fieldstation B are at stop, and the route designating means is restored toits normal condition as has been described, the relay 11- 12F becomespicked up to complete the restoration to normal conditions of thecontrol apparatus associated with field station B.

When the westbound train has passed signal 13 so as to cause the pickingup of relay 13-14PK by a mode of operation similar to that which hasbeen described in detail for the picking up of a similar relay NPK atfield sation A, the through route description storage relay CRZ becomesdropped away by the opening of back contact 97 of relay 13-14PK, and thedropping away of that relay causes the dropping away of the relay 13G bythe opening of front contact 49. Relay 13G in dropping away causes thedropping away of route relay 13RR by the opening of front contact 112,and the dropping away of relay 13RR is effective toautomatically-initiate the code communication apparatus into a cycle ofoperation for restoring relays in the field at field station C by a modeof operation comparable to that which has been described as beingeffective for field station A in accordance with the dropping away ofthe relay 10G. An indication is received at the control office fromfield station C causing the restoration of the relay 13-14PK to itsdropped away position, and the relay 11i-MF becomespicked up by theenergization of a circuit that has been described when considering thenormal conditions of the system.

The Iautomatic route control apparatus at the control office has thusbeen restored to its normal conditions, rand is thus conditioned stationby sta-tion as the route is released in the rear of e. westbound .trainso that another route may be set up for a following westbound trainaccording lto `a mode of operation similar to that which has beenheretofore described.

Semi-Automatic Operation Under semi-automatic operation, the selectorlever AM for the associated station is operated to its center position.With the lever AM for a station in its center position, operation iseffective as has been described when considering full automaticoperation up to the point of picking up the particular route relay RRthat has been selected by the automatic circuits. The picking up of theroute relay RR requires manual actuation of an associated route pushbutton for the particular route that has been selected. In other words,under semiautomatic operation, only partial routes corresponding to thethrough route description may be established. This provides a check onthe manipulation of the buttons by the control machine operator toprevent him from setting up the Wrong route by inadvertently actuatingthe wrong route button. On the other hand, the Semi-automatic operationgives the operator of the control machine an opportunity to control thepropagation of the establishment of partial routes so as to permit themanual designation of preference where two c'oniiicting routes 11through a tield station are called for at substantially the same time.

To consider the circuit organization more specically lfor theenergization of a route relay RR under semi-automatic operation, it willbe assumed that a through route description has been set up as has beenheretofore described for the passage of a westbound train from signal tosignal 17, and that the control has been ettective to apply energy tothe control circuit for the route relay MRR. Under normal operation, therelay MRR. is picked up by a circuit including contact 89 of lever11-12AM inv its lefthand position, but with this lever in its centerposition for semi-automatic operation, contact 80 of lever 11-12AM isopen. It the route push button 11PB is actuated to its depressedposition, however, the relay 11RR becomes picked up because of shuntingaro-und the contact 80 of lever 11-12AM by contact 134 of `lever 11-1ZAMin its center position being connected in series with contact 135 ofbutton 11PB in its depressed position. When relay 11RR is picked up uponactuation of the route push button HPB, it is maintained energizedthrough stick contact 136, which is connected through contact l135 ofthe push button 11PB in its normal position. This contact 13S ispreferably provided with a make-before-break adjustment so that thestick circuit is maintained established during the restoration of thebutton 11PB to its normal position from its depressed position. Thetransmission of the controls for establishment 'of the route upon thepicking up of relay 11RR is provided according to the same mode ofoperation that has been heretofore described relative to full automaticoperation of the system. It will be noted that a similar organization ofcontacts of the lever 11-12AM are included in the circuit for thecontrol of the route relay 12RR which is associated with the clearing ofsignal 12, Vand it is to be understood that a similar mode of operationis provided in the picking up of this route relay.

Full Manual Control For operation under full manual control at anystation, the selector lever AM at that station is operated to -itsrighthand position. With the lever AM in its right- :hand position theroute relays RR are subject to energizationv when their associated pushbuttons are actuated, irrespective ofany through route description thatmay havebeen set up.

More specifically, for example, if the lever 11-12AM is operated to itsfull right-hand position, the pick up circuit for the route relay .HRRis no longer dependent upon the closure of front contact 79 of relay11G, and

thus the picking up of relay HRR can be rendered effective independentof the storage of a through route description. button 11PB to itsdepressed position when the lever 11-12AM is in its right-hand position,relay MRR becomes picked up by the energization of a circuit extendingfrom ('-j-), including back contact 78 of relay MRR, lback contact i137of relay 11-12PK, contact 134 of lever 11-12AM in its right-handposition, contact 135 of button 11PB in its depressed position andwinding of relay HRR, to This relay, ,when picked up, closes a stickcircuit at front contact 136 to maintain the relay picked up afterrestoration of the push button 11PB to its normal position. Relay HRRwhen picked up initiates the code communication system intoV a cycle ofoperation for the transmission of track switch and signal controls toestablish the route governed by signal 11 by a mode of operation thathas been heretofore described.

ManualV Cancellation After a through route description has been set upby the energization of a relay RS, such route description can becancelled by the pulling out of the push button PB that is associatedwith the control of that relay. Thus, if it is desired to cancel theroute description that has been set up by the picking up of the relayRSZ, lfor eX- Thus, upon actuation of the route pushV ample, the pullingout of the push button IGPBZ causes the picking up of the cancel relayIGCR by the energize.- tion of a circuit extending from including backcontact 138 of relay 11-12CP, contact 139 of button ltPBZ in itspulled-out position and winding of slow drop away relay NCR, to Thepicking up of this relay closes a stick circuit through Contact 140 toshunt the push button contact 139 of the circuit just described.

The picking up of relay 10CR causes the picking up of the cancel relay11-12CP which is associated with station B by the energization of acircuit extending from a 0+), including back contact 141 of relay ltlGK,front contact 142 of relay IGCR, back contact 143 of relay A-BPi' andwinding of relay 11-12CP, to This relay when picked up causes thedropping away of the corresponding through route description relay BRZwhich is associated with station B by the opening of its circuit at backcontact 68, and Ithe opening of back contact 138 in the circuit forrelay ltlCR causes relay lCR to be restored to its normally deenergizedcondition. This in turn causes the dropping away of relay 11-12CP by theopening of front contact 142 of relay llilCR.

The above described route description storage cancellation is effectiveprovided that there has been no route actually established, and providedthat the route for which cancellation is attempted is not occupied by atrain. Under such conditions, emergency cancellation means is providedby the push button CPB for the several iield sta-tions, but these pushbuttons are normally sealed, and there is little occasion for theiractuation.

To consider the mode of operation under such conditions of cancellation,however, if the seal associated with push button B-CPB, for example, isbroken, and that push button is actuated to its depressed position, thecancellation relay 11-12CP is picked ,up by the energization of anobvious circuit, and the picking up of this relay renders cancellationeffective for station B by a mode of operation that has been described.

It is further provided that when an operator actuates the selector leverAM for a particular field station to a semi-manual or full-manualposition, the cancellation relay for the associated station is pickedup, provided there is no signal clear for governing entra-nce for atrain into the associated eld station. Thus, the relay 13-14CP, forexample, is picked up upon the actuation of the lever Y11-12AM to itssemi-manual or full-manual position by the energization of a circuitincluding back contact 144 of relay llGK, contact 145 of lever 11-12AM,back contact 146 of relay B-CPr and winding of relay 13-14CP, to Thepicking up of this relay Vcancels any description that may be set up bya relay CR for the field station C by the opening of circuits governingthese relays at back contact 9S.

Having thus described a centralized traffic control system as applied tothe control of a specific stretch of trackwa-y, it is desired to beunderstood that this form is selected to facilitate in the disclosure ofthe invention rather than to limit the number of forms which theinvention may assume, and it is to be further understood that variousadaptations, alterations and modifications may be applied to thespecific form shown to meet the requirements of practice without in anymanner departingfrom the spirit or scope of the present invention exceptas limited by the appending claims.

What I claim is:

1. A centralized tratiic control system for a stretch of railway trackhaving track switches and signals for the establishment of partialroutes at several remotely spaced eld stations subject to control from acontrol oice comprising, code communication means for two way codecommunication between the control oice and the eld stations, indicationmeans including said code communication means for indicating at thecontrol oiice the presence of a train at the several iield stations, acontrol panel assenze having route buttons for the several fieldstations for designation of respective partial routes extending throughthe associated field stations, said control panel having a manualcontrol switch for each of the field stations having one position forautomatic control and another position for semi-automatic control, routedescription storage means at the control office for storing descriptionsof through routes extending from a predetermined entering point throughseveral field stations to different points of departure, and partialroute establishing means associated with the several field stations andincluding said code communication means for setting up respectivepartial routes and clearing signals governing entrance theretorespectively in advance of a train, said partial route establishingmeans being rendered effective in response to the actuation of saidindication means to establish a partial route conforming to a throughroute for a train as called for by said storage means provided saidlever for the associated field station is in said one position withoutrequiring actuation of one of said route buttons, and said partial routeestablishing means being effective for a field station having itsselector lever in said semiautomatic position in response to theactuation of said indication means only provided a particular one ofsaid route buttons corresponding to the route called for by said storagemeans is actuated.

2. A centralized traffic control system for a stretch of track havingtrack switches and signals for the establishment of partial routes atseveral remotely spaced field stations subject to control from a controloffice comprising, code communication means for two way code.communication between the control office and the field stations,indication means including said code communication means for indicatingat the control office the presence of a train at the several fieldstations, a control panel at the control office having route buttons forthe several field stations for designation of respective partial routesextending through the associated field stations, said control panelhaving a manual control switch for each of the field stations having oneposition for selection of automatic control and having another positionfor selection of manual control, route description storage means at thecontrol office for storing descriptions of through routes extending froma predetermined point of entrance through several field stations todifferent points of departure, and partial route establishing meansassociated with the several field stations and including said codecommunication means for setting up respective partial routes in advanceof a train and clearing a signal, said partial route establishing meansbeing rendered effective in response to the actuation of said indicationmeans to establish a partial route conforming to a through route for atrain as called for by sa-id storage means provided that said lever forthe associated field station is in said one position, and said partialroute establishing means being effective for a field station having itsselector lever in said another position only upon the actuation of anyone of said route buttons, irrespective of a through route that may becalled for by said route description storage means.

3. A centralized traffic control system for a track layout having atleast one entrance point and a plurality of points of departure forthrough routes extending through the track layout and having trackswitches and signals at several remotely spaced field stations in theroutes subject to control from a control office comprising:

(a) code communication means for communicating switch and signal controlcodes from the control office to the field stations and forcommunicating indication codes from the field stations to the controloffice indicative of the conditions of devices at the several fieldstations,

(b) route description storage means at the control office for storingthe designation of any one of several points of departure from saidtrack layout for a train 14M entering said stretch at one of theentrance points of said track layout,

(c) indication means at the control office responsive to indicationcodes transmitted from the field stations by said code communicationmeans for indicating the presence of a train at each of the fieldstations,

(d) partial route establishing means operable when rendered effectivefor setting up a partial route and clearing a signal in advance of atrain at each field station conforming to the route leading to any oneof said points of departure of the train as called for by said routestorage means,

(e) and means for rendering said partial route establishing meanseffective for setting up a route and clearing a signal at each fieldstation in response to the actuation of said indicating means forindicating the presence of a train at a point in approach to eachrespective station.

4. A centralized traffic control system according to claim 3 whereinsaid route description storage means at the ycontrol office includes abank of storage relays and means for selectively energizing the storagerelays in different combinations in accordance with different designatedpoints of departure.

5. A centralized traffic control sys-tem according to claim 4`Whereinsaid means for selectively energizing the storage relays is responsiveto an indication communicated from one of the field stations by saidcode communi'cation means.

6. A centralized traffic control system for a track layout having aplurality of through routes extending from an entrance point to aplurality of points of departure respectively and having track switchesand signals at several remotely spaced field stations in the routessubject to control from a control office comprising:

(a) code communication means for communicating switch and signal controlcodes from the control office to the field stations and forcommunicating indication codes 'from the field station to the controloffice indicative of conditions of devices and indicative of thepresence of trains at the several field stations,

(b) a through route ldescription storage means at the control office foreach of the several field stations for storing a description indicativeof the point of departure of any one of said through routes,

(c) indication means at the control office responsive to indicationcodes transmitted from the field stations by said code communicationmeans for lindicating the presence of a train at each of the fieldstations,

(d) route storage transfer means including said code communication meansfor advancing a through route description storage in said routedescription storage means from one of said storage means to the next ina predetermined order in response to the reception of a particularindication code by said indication means indicative of the progress of atrain,

(e) said route storage transfer means being effective upon the transferof a route storage to initiate said code communication means intooperation for the transmission from the control office to the fieldstations of switch and signal control codes for the establishment of apartial route selected in accordance with the point of departure storagethat has been transferred,

(f) and means at the field stations for controlling track switches andsignals in accordance with the switch and signal control codeslcommunicated by said code communication means from the control office.

7. A centralized traffic control system according to claim 6 whereinmanually operable means is provided for controlling said switch andsignal control code selecting means and wherein switching means isprovided for rendering said switch and signal control code selectingmeans lselectively responsive to said manually operable means or to saidstorage means. i

8. A centralized trafiic control system for a track layout having aplurality of conicting through routes extending from an entrance pointto at least one point of departure, each of the routes having trackswitches and signals at several remotely spaced field stations in theroutes subject to control from a control olice comprising:

(a) code communication means for communicating switch and signal controlcodes from the control ofce to the iield stations and for communicatingindication codes from the field stations to the control oice indicativeof conditions of devicesand indicative of the presence of trains at theseveral eld stations,

(b) through route description storage means at the control oice forstoring a description of at least one of said through routes that may bedesignated including track switches and signals at a plurality of eldstations, and

(c) partial route'establishing means for each ofthe stations operable inresponse to the reception at the control oice of an indication code'indicative of the presenceV of a train at one field station fortransmitting selected switch and signal control codes from the controloice to only a single field station in advance of the train to establisha partial route corresponding to the description stored by said throughroute description storage means,

(d) whereby a through route corresponding to a designated through routedescription is set up by partial route establishment, through one fieldVstation at a time, as-the train progresses.

9. A centralized trafiic control system for a track layout having trackswitches and signals at remotely spaced eld stations controlled from acontrol oce for the selective establishment of a plurality of throughroutes extending between an entrance point and a plurality of points ofdeparture from the track layout comprising:

(a) code commtmication means for communicating switch and signal controlcodes from the control ofiice to the iield stations and forcommunicating indication codes from the field stations to the controlotlice indicative of conditions of devices and indicative of thepresence of trains at each of the eld stations,

(b) route description storage means at the control oftice for storing adesignated description of a through route extending from the entrancepoint through several eld stations to any one of the points ofdeparture,

(c) indication registration means at the control oice actuated by anindication code transmitted from one of the eld stations by said codecommunication means in response to the passage of a train forregistering an indication at the control oiice of the presence of thetrain,

(d) partial route establishing means including'said code communicationVmeansoperable' in response to the actuation of said registration meansfor clearing a signal and setting upa partial route in advance of thetrain conforming to said designated description of a through route,

(e) and means for rendering said partial route establishing meanseffective for setting up a partial route at a given station onlyprovided there is no conflicting route established-at that station.

VReferences Cited inthe file of this patent UNITED STATES PATENTS2,194,353 Brown Mar. 19, 1940 Y 2,223,126 Phinney Nov. 26, 19402,399,734 Hailes May 7, 1946 2,439,676 Seitz Apr. 13, 1948 i 2,443,199Schmidt June l5, 1948 2,700,728 Brixner Jan. 25, 1955 2,793,287 PhelpsMay 2l, 1957 V2,916,612 Marple l Dec. 8, 1959

